An interventional study of Lower extremity compression garments and Without compression garments in Single-ventricle and Fontan Circulation, sponsored by University of Texas Southwestern Medical Center. Recruiting at 1 site in United States. Open to participants aged 18 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-07-30.
Sponsored by University of Texas Southwestern Medical Center · Not applicable, Interventional, and Other
The aim of this study is to investigate whether venous compression garments increase exercise stroke volume in patients with Fontan circulation. To address this aim, we will test the following hypotheses:
Participants will:
Participants will:
Study Day 1 - Consent, Screening and Garment Measurements:
Following assessment of participant eligibility, all participants will undergo leg venous ultrasound assessment and abdominal-foot measurements for the custom making of compression garments.
Study Day 2 - MRI:
Study participants will undergo comprehensive cardiovascular MRI using a 3T MRI scanner with and without compression garments and exercise.
Study Day 3 - Cardiovascular \& Exercise Testing Day:
All participants will undergo comprehensive cardiovascular structure and function assessments at rest and during exercise with and without the wearing of compression garments. Baseline testing will include dual x-ray absorptiometry (DEXA), pulmonary function testing, comprensive vascular assessments and echocardiography. During exercise at two submaximal workloads, the study team will measure blood pressure, oxygen uptake and cardiac output.
86 studies on the registry are indexed under Univentricular Heart; 22 are open to participants now.
This study's planned enrollment of 20 is below the median of 28 across 44 interventional studies indexed under Univentricular Heart.
Browse Univentricular Heart studies →University of Texas Southwestern Medical Center is the lead sponsor of 1,010 studies on the registry; 199 are open to participants now.
Of its 139 completed or terminated interventional studies of FDA-regulated products, 105 (76%) have results posted.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Patients with a Fontan circulation -
Inclusion criteria:
Exclusion Criteria:
Healthy Controls:
Healthy control participants will be recruited on the basis of having no known chronic diseases and not currently taking any cardiovascular medications.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Fontan circulation participants will undergo Rest +Submax exercise with and without wearing venous compression garments. A subset of patients with Fontan circulation will undergo repeat testing 2-weeks later.
Device: Lower extremity compression garments · Other: Without compression garments
Healthy group participants will undergo Rest +Submax exercise with and without wearing venous compression garments.
Device: Lower extremity compression garments · Other: Without compression garments
Acute and 2-week effects of compression garments
Acute effects without compression garments
Change in Stroke Volume with Exercise
The change in single ventricular stroke volume from rest to moderate intensity exercise with compression garments during baseline testing
Time frame: Rest (20 minutes), Exercise (10 minutes)
Change in Stroke Volume with Exercise
The change in single ventricular stroke volume from rest to moderate intensity exercise without compression garments during baseline testing
Time frame: Rest (20 minutes), Exercise (10 minutes)
Change in Stroke Volume with Exercise
The change in single ventricular stroke volume from rest to moderate intensity exercise following 2 weeks of wearing compression garments.
Time frame: Rest (20 minutes), Exercise (10 minutes) at 2-weeks follow-up testing
The Acute Effect of Compression Garments on Stroke Volume during Exercise
The difference in the change in single ventricular stroke volume during moderate intensity exercise between baseline testing with (outcome #1) and without (outcome #2) garments
Time frame: Rest (20 minutes) and Exercise (10 minutes) repeated during baseline testing
The Chronic Effect of Compression Garments on Stroke Volume during exercise
The difference in the change in single ventricular stroke volume during moderate intensity exercise between baseline testing without garments (outcome #2) and following 2 weeks of wearing compression garments (outcome #3) in patients with Fontan Circulation.
Time frame: Rest (20 minutes) and Exercise (10 minutes) completed during baseline and during follow-up testing
Change in Venous Return with Exercise
The change in inferior vena cava flow from rest to moderate intensity exercise with compression garments using MRI during baseline testing
Time frame: Rest (10 minutes) and Exercise (5 minutes)
Change in Venous Return with Exercise
The change in inferior vena cava flow from rest to moderate intensity exercise without compression garments using MRI during baseline testing
Time frame: Rest (10 minutes) and Exercise (5 minutes)
Change in Venous Return with Exercise
The change in inferior vena cava flow from rest to moderate intensity exercise following 2 weeks of wearing compression garments using MRI
Time frame: Rest (10 minutes) and Exercise (5 minutes)
The Acute Effect of Compression Garments on Changes in Venous Return with Exercise
The difference in the change in inferior vena cava flow during moderate intensity exercise between baseline testing with (outcome #6) and without (outcome #7) garments
Time frame: Rest (10 minutes) and Exercise (5 minutes) repeated during baseline testing
The Chronic Effect of Compression Garments on Changes in Venous Return with Exercise
The difference in the change in inferior vena cava flow during moderate intensity exercise between baseline testing without garments (outcome #7) and following 2 weeks of wearing compression garments (outcome #8) in patients with Fontan Circulation.
Time frame: Rest (10 minutes) and Exercise (5 minutes) completed during baseline and during follow-up testing
Plan to share: No
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